How did you sleep last night? It can happen to anyone that they don’t rest enough or well, and suffer the consequences throughout the day. If you feel unhappy or anxious first thing in the morning, it could be because of how you spent the night. Sleep deprivation can greatly affect our mood and mental health. An adult needs at least seven hours of rest and in this case quality is just as important as quantity: even if you sleep enough, disturbed or fragmented sleep can still have negative effects. And when you don’t reach the recommended minimum, the toll can be high: several studies have linked poor sleep quality to an increased risk of obesity, heart disease and dementia, as well as mood disorders.
Now, a systematic review with meta-analysis of 154 studies conducted on over 5 thousand people over 50 years has quantified the effects of various forms of sleep loss on multiple aspects of emotional experiences, revealing the direct consequences of interrupted or restless sleep on the anxiety, depression and bad mood.
Sleep well? Here’s what every age needs by Donatella Zorzetto 10 July 2023
Emotional changes
“We discovered that all forms of insomnia, from total deprivation to partial loss, up to fragmentation due to continuous awakenings, cause emotional changes – explains the professor Cara Palmerof the Sleep and Development Lab della Montana State University –. The strongest and most consistent effect highlighted is that even minimal sleep loss reduces positive mood. Now we know that it also increases anxiety and, if emotional events occur, you are more likely to react negatively than well-rested people.”
This is because lack of sleep makes us feel “less emotional arousal, changing how we feel the intensity of certain emotions in our body, which suggests that overall we experience more muted positive emotional responses.”
According to international estimates, more than 30% of adults have a daily sleep debt of more than an hour, while almost one in 10 adults falls short of the minimum level of rest by two or more hours each night. “Across the world, individuals rarely get the recommended amount of sleep for at least 5 nights a week – underlines the professor Jo Bower from the East Anglia in Norwich, who conducted this research -. Our work shows the potential consequences of this situation on our emotional health, at a time when mental health problems are rapidly increasing.”
Now the new study published in the journal Psychological Bulletin dell’American Psychological Association explored the issue in depth, underlining strong connections between mental health and sleep, with serious consequences on anxiety, depression, mood and response to emotional stimuli.
The body, not the brain, regulates sleep by Valentina Arcovio 15 September 2023
The study on 50 years of research
This study synthesizes more than 50 years of experimental research on sleep and emotion and provides strong evidence of how periods of prolonged wakefulness, reduced sleep duration, and nocturnal awakenings negatively impact human emotional functioning, increasing the risk of psychiatric disorders. “In general, total sleep deprivation had a greater impact on mood and emotions than partial loss or fragmentation – confirms Palmer -. However, it is interesting to note that the effect on positive mood occurs immediately, even after short periods of insomnia, while anxiety worsens with the loss of deep REM sleep.”
Studies included in the meta-analysis found that people with poor quantity and quality of sleep reported feeling more stressed, angry, sad and mentally exhausted. And when they started sleeping normally again, they saw a marked improvement in their mood.
But what is it about sleep that makes our body behave this way? “The answers are found in the brain – says the expert -. We know from previous research that insomnia has an impact on the neural circuits involved in the experience of reward or positive experiences, which probably plays a role. We have also noticed reactions more intense in the areas of the brain involved in emotional experiences. And at the same time we saw alterations in the connections between the emotional centers of the brain and the prefrontal cortex, which helps us to appropriately control our reactions.”
Thus sleep “cleans” the brain
During slow-wave sleep, the body eliminates potentially harmful materials from the brain, such as beta-amyloid proteins that cause Alzheimer’s. The REM phase, on the other hand, is when we dream and in which information and experiences are consolidated and stored in the memory. This is why they are both important, but in different ways. Deep sleep is considered one of the best indicators of quality rest because a person must get a relatively uninterrupted seven to eight hours of sleep to complete a 90-minute cycle. Slow-wave sleep, on the other hand, may be linked to the brain’s reward centers, which influence responses to positive emotional situations. Hence the bad mood if you sleep less than expected. And it is also obstructive apnea that has an influence, so much so that from the data it emerges more frequently in people with psychiatric pathologies.
Depression, a sleepless night reduces the symptoms by Celeste Ottaviani 03 December 2023
“Longer periods of wakefulness lead to more extreme depressive or anxious symptoms,” concludes Professor Palmer. “It is likely that sleep loss may affect people who are already depressed or have a genetic risk of depression differently. For example, some of the Our previous work suggests that already anxious individuals may have exaggerated responses to loss of rest, just as chronic insomnia may increase the risk of developing a mood disorder, depression, or anxiety.” Not surprisingly, “insomnia is also a reliable predictor of depression.” That’s why “in a largely sleep-deprived society, quantifying the effects of sleep loss on emotions is critical to promoting psychological health. And giving yourself time to sleep is an important act of self-care that should absolutely neglected, such as eating well and exercising”.